Personal data terminals ("PDTs") are an indispensable component in computer communications networks. In such systems, a number of PDTs are interfaced with data communications equipment (DCE), for example, a modem, mainframe computer or data communications network, thereby allowing individual PDT operators ("users") to monitor and access data from the DCE. Often the PDTs are placed in busy, noisy environments. In such environments, important messages transmitted over the DCE network may be missed by a PDT user who is distracted or otherwise not able to attentively monitor the PDT. Accordingly, there is a need for an apparatus that will automatically monitor the network and notify the user of important message transmissions.